Costa Rica's national Emergency Commission has declared a medium-level alert after an eruption of ash at the Turrialba volcano.

The commission says ash fell in a radius of about 2 miles (3 kilometers) from the peak, affecting some small nearby communities. The 10,958-foot (3,340-meter) volcano is 42 miles (70 kilometers) east of San Jose, the capital.

The commission said in a statement Tuesday that authorities evacuated 21 people from a community near Turrialba. The national park that includes the volcano will be closed to visitors.

Activity at the volcano has increased in recent months. The last major eruption there occurred 145 years ago.